JRPass

Hi there!

Here are some answers for you:

Osaka to Nagano? Does this go through Tokyo?

Yes, it is possible, and yes you should transfer at Tokyo for the fastest route to Nagano on the Asama bullet train

and then from Nagano to Tokyo?

Yes, this is also possible on the Asama bullet train.

What would be the aprox price? (travelling from december 7th to 13)

Here is a breakdown of the costs (using an earlier date of travel, so prices may change)

1. Osaka > Nagano: ¥11170, (267mins, 441km)
2. Nagano > Tokyo: ¥7770, (106mins, 222km)

TOTAL: ¥18940 for 2 legs

Hope this helps!